Atazanavir / cobicistat Side Effects

In Summary

More frequently reported side effects include: first degree atrioventricular block. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to atazanavir / cobicistat: oral tablet, tablet oral

In addition to its needed effects, some unwanted effects may be caused by atazanavir / cobicistat. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking atazanavir / cobicistat:

More common:

Abdominal or stomach pain

chills

clay-colored stools

dark urine

dizziness

fever

headache

itching or rash

loss of appetite

nausea

unpleasant breath odor

unusual tiredness or weakness

vomiting of blood

yellow eyes or skin

Incidence not known:

Abdominal or stomach fullness or tenderness

black, tarry stools

blistering, peeling, or loosening of the skin

blood in the urine

chest pain

clay colored stools

decreased appetite

diarrhea

gaseous abdominal or stomach pain

joint or muscle pain

pain in the groin or genitals

painful or difficult urination

recurrent fever

red skin lesions, often with a purple center

red, irritated eyes

sharp back pain just below the ribs

sore throat

sores, ulcers, or white spots in the mouth or on the lips

swelling of the feet or lower legs

swollen glands

unusual bleeding or bruising

For Healthcare Professionals

Applies to atazanavir / cobicistat: oral tablet

General

In clinical trials, safety of this drug was evaluated in HIV-1-infected, antiretroviral therapy-naive patients using the individual components with other antiretrovirals for at least 48 weeks. In 1 trial, atazanavir and cobicistat were used with emtricitabine-tenofovir (cobicistat-boosted group); in another trial, atazanavir and ritonavir were used with emtricitabine-tenofovir (ritonavir-boosted group). In the cobicistat-boosted group, the most common side effects were jaundice, ocular icterus, and nausea; in the ritonavir-boosted group, the most common side effects were jaundice, ocular icterus, nausea, and diarrhea. Study treatment was discontinued due to side effects in 7% of patients in both the cobicistat- and the ritonavir-boosted groups. Most of the side effects included from clinical trials were of at least moderate intensity (grade 2 or higher).

The manufacturer product information for atazanavir and cobicistat should be consulted for additional safety information.[Ref]

Hepatic

Increases in total bilirubin greater than 2.5 times the upper limit of normal (2.5 x ULN) was reported in 65% of patients in the cobicistat-boosted group and 56% in the ritonavir-boosted group. Increased ALT (greater than 5 x ULN), AST (greater than 5 x ULN), and GGT (greater than 5 x ULN) were reported in 3%, 3%, and 2% of patients in the cobicistat-boosted group, respectively, and 2%, 2%, and 1% of patients in the ritonavir-boosted group, respectively.

Jaundice was reported in the cobicistat-boosted group (all grades: 13%; grades 2 to 4: 5%) and the ritonavir-boosted group (all grades: 11%; grades 2 to 4: 3%).

Most patients taking atazanavir experienced asymptomatic elevations in indirect (unconjugated) bilirubin related to inhibition of UGT. This hyperbilirubinemia was reversible upon discontinuation of atazanavir.[Ref]

Nausea was reported in the cobicistat-boosted group (all grades: 12%; grades 2 to 4: 2%) and the ritonavir-boosted group (all grades: 11%; grades 2 to 4: 2%). Diarrhea (all grades) was reported in 11% of patients in the ritonavir-boosted group.

Increased serum amylase (greater than 2 x ULN) was reported in 4% and 2% of patients in the cobicistat-boosted and ritonavir-boosted groups, respectively.

If serum amylase was greater than 1.5 x ULN, lipase was also measured. Increased lipase (grades 3 to 4) was reported in 9% and 6% of patients in the cobicistat-boosted and ritonavir-boosted groups, respectively.[Ref]

Musculoskeletal

Increased creatine kinase (at least 10 x ULN) was reported in 5% and 6% of patients in the cobicistat-boosted and ritonavir-boosted groups, respectively.[Ref]

Renal

Nephrolithiasis has been reported with atazanavir. In clinical trials, nephrolithiasis was reported in 2% of patients in the cobicistat-boosted group and no patients in the ritonavir-boosted group. Onset of nephrolithiasis was about 24 weeks in the cobicistat-boosted group.

In clinical trials, serum creatinine increased and estimated CrCl decreases occurred early during therapy in the cobicistat-boosted group after which they stabilized. After 48 weeks of therapy, eGFR (based on CrCl) change averaged -13.4 mL/min in the cobicistat-boosted group and -9.1 mL/min in the ritonavir-boosted group.

Renal impairment (including acute renal failure and Fanconi syndrome) has been reported when cobicistat was used in a regimen containing tenofovir.

In clinical trials over 48 weeks (n=771), 6 (1.5%) patients using atazanavir, cobicistat, and tenofovir discontinued therapy due to a renal side effect; 5 patients had laboratory findings consistent with proximal renal tubulopathy. None of the 5 patients had baseline renal dysfunction (e.g., estimated CrCl less than 70 mL/min). Laboratory findings in these 5 patients improved but did not completely resolve in all patients when therapy was stopped. No patients required renal replacement therapy.[Ref]

Genitourinary

Increased urine RBC (greater than 75 RBC/high power field) and urine glucose (at least 1000 mg/dL) have been reported in 3% and 3% of patients in the cobicistat-boosted group, respectively, and 2% and 1% of patients in the ritonavir-boosted group, respectively.[Ref]

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